Hot melt adhesives are widely used in the packaging industry to seal cardboard cases, trays and cartons.
Many types of packaging applications require the use of an adhesive that is both heat resistant and cold tolerant. The use of hot melt adhesives is widely used in packaging industry to seal containers, e.g. cardboard cases, trays and cartons. The hot melt adhesive used to seal the containers must have good heat resistance and good cold resistance during transportation and storage. Sealed containers being transported and/or stored within a truck or rail car are exposed to very high temperatures in the summer (up to 165° F. or higher) and very low temperatures in the winter (down to about −20° F. or lower). Thus, hot melt adhesives used in packaging applications need to be strong enough such that the sealed containers will not pop open during the transportation process.
Traditional hot melt adhesives are applied onto the containers at elevated temperatures, often around 350° F. for proper application. However, high application temperature has several drawbacks, e.g. thermal degradation of adhesives, downtime due to charring of the plugged nozzles, high maintenance cost, safety hazards, high volatile organic chemicals, and high energy consumption. Hence, there is a need for a low application temperature hot melt adhesive with good heat resistance and cold resistance. The current invention addresses this need.